1. Field of the Invention
The present invention is directed to a sealed electric switch, and more particularly to a sealing structure between a molded switch housing and a separately formed cover by means of a seal member which is additionally molded on the switch housing.
2. Description of the Prior Art
For sealing of electric switches composed of a switch housing and a cover, it has been a general practice to interpose an annular seal member between peripheral mating surfaces of the housing and the cover. The prior art suggests that it is effective, particularly for miniature electric switches, to form the seal member as being additionally molded on the peripheral mating surface of the switch housing for secure and precise positioning thereof. Such additional molding can be effected by an injection molding which, as typically shown in FIG. 13, utilizes separable molding dies 1 and 2 to hold the switch housing 10 therebetween and injects an elastic material to form the annular seal member 40 around the top periphery of the switch housing 10. In the figure, the switch housing 10 is shown with its top contact mounting surface lying in the plane of the paper. In this structure, however, there remains a problem that, as shown in FIG. 13, when separating the molding dies 1 and 2 after injection-molding of the seal member 40, the seal member 40 is likely to be pulled in the separating directions of the dies 1 and 2 to thereby leave partial separations from the switch housing 10, which eventually lowers and even nullify the sealing between the switch housing and the cover.